[llvm-dev] [RFC] arm64_32: upstreaming ILP32 support for AArch64

[Tim Northover via llvm-dev]

On Wed, 6 Feb 2019 at 21:29, Eli Friedman <efriedma at quicinc.com> wrote:
> Like you say, I'm pretty sure the problems you mentioned are solvable.  And you don't actually have to solve every possible inefficiency to get a usable result; it's not the end of the world if we emit an unnecessary zero extension somewhere.

True, though they'd have to be pretty small edge cases. And the
biggest job (intrinsics) might well be the most important since both
NEON and prefetch tend to be used in performance-critical code.

> I'm mostly worried that you'll continue to discover new issues forever because nobody else has a target that differs in that particular dimension.

I'd actually be more worried with the pass-based version. From what I
remember only the icmp and not-inbounds GEP were really surprising in
the original attempt. This time around I was hitting a lot more
edge-cases that need special handling, a trend that I suspect would
continue.

Cheers.

Tim.